ch 16 Jarvis Ears Flashcards
the external ear, the middle ear, and the inner ear
three parts of ear
is called the auricle or pinna and consists of movable cartilage and skin
external ear
serves to funnel sound waves into its opening
-terminates at the eardrum, or tympanic membrane (TM)
external auditory canal
is lined with glands that secrete cerumen, a yellow, waxy material that lubricates and protects the ear.
canal (of the external auditory canal)
forms a sticky barrier that helps keep foreign bodies from entering and reaching the sensitive tympanic membrane.
wax
migrates out to the meatus by the movements of chewing and talking.
Cerumen (waxy stuff)
separates the external and middle ear and is tilted obliquely to the ear canal, facing downward and somewhat forward. It is translucent with a pearly gray color and a prominent cone of light in the anteroinferior quadrant, which is the reflection of the otoscope light
tympanic membrane (TM)
is oval and slightly concave, pulled in at its center by one of the middle ear ossicles, the malleus
drum
; these are the umbo, the manubrium (handle), and the short process.
parts of the malleus show through the translucent drum
small, slack, superior section of the TM is called the
pars flaccida (part of tm)
remainder of the drum, which is thicker and more taut, is the
pars tensa(part of tm)
is the outer fibrous rim of the drum
annulus(part of tm)
flows to the parotid, mastoid, and superficial cervical nodes.
Lymphatic drainage of the external ear
is a tiny air-filled cavity inside the temporal bone
middle ear
the malleus, incus, and stapes
-outer ear is covered by the tympanic membrane
tiny ear bones, or auditory ossicles (middle ear)
are the oval window at the end of the stapes and the round window
openings to the inner ear
Another opening is? , which connects the middle ear with the nasopharynx and allows passage of air
- tube is normally closed, but it opens with swallowing or yawning.
- Retracted drum due to vacuum in middle ear with obstructed eustachian tube
the eustachian tube
(1) it conducts sound vibrations from the outer ear to the central hearing apparatus in the inner ear;
(2) it protects the inner ear by reducing the amplitude of loud sounds;
(3) its eustachian tube allows equalization of air pressure on each side of the tympanic membrane so the membrane does not rupture (e.g., during altitude changes in an airplane)
middle ear has three functions
, which holds the sensory organs for equilibrium and hearing
bony labyrinth (inner ear)
Within the bony labyrinth, the vestibule and the semicircular canals comprise the ?, and the cochlea
vestibular apparatus (inner ear)
contains the central hearing apparatus
cochlea (inner ear)
, the bony prominence behind the lobule, is not part of the ear but is an important landmark.
mastoid process
peripheral, brainstem, and cerebral cortex
function of hearing involves the auditory system at three levels:
the ear transmits sound and converts its vibrations into electrical impulses, which can be analyzed by the brain
peripheral level